Yarn texturing apparatus



Jan. 3, 1967 E. K. M INTOSH YARN TEXTURING APPARATUS Filed Oct. 28, 1963 INVENTOR. EUELL K. MCINTOSH ATTORNEY United States Patent Ofilice Patented Jan. 3, 1967 3,295,181 YARN TEXTURING APPARATUS Euell K. McIntosh, Pensacola, Fla., assignor to Monsanto Company, a corporation of Delaware Filed Oct. 28, 1963, Ser. No. 319,294 7 Claims. (Cl. 2871.3)

The present invention concerns apparatus for drawing yarn, and more particularly to such apparatus incorporating a novel and improved draw pin construction.

In the textile and related arts, spun yarn is fed at a given speed to a drawing region and is simultaneously withdrawn therefrom at a higher speed, as by a draw roll, thereby elongating or drawing the yarn to orient the molecules in the individual filaments. Greater yarn uniformity and improved yarn properties result from wrapping one or more turns of the yarn around a fixed draw pin located in the draw region, to localize the point at which the yarn necks down to a smaller diameter. Known draw pins are typically provided with a ceramic cylindrical surface having closely controlled surface frictional characteristics. Constant running of the yarn on a given path on the draw pin polishes the surface of the pin, changing the frictional characteristics of this path and causing the yarn to tend to shift axially along the draw pin to a new equilibrium position presenting lower frictional drag on the yarn. If the draw pin axis were parallel to the draw roll axis, the yarn would eventually shift entirely off the draw pin, or sufficiently far that the yarn would slip off the end of the draw roll. The draw pin was accordingly mounted to be skewed with respect to the axis of the draw roll, to

positively locate the yarn. However, this constrained the yarn to run in a single narrow path on the draw pin, producing relatively rapid localized surface wear. By conventional prior art practices, the draw pins had to be periodically removed and have their surfaces renewed or refinished as by grinding and lapping.

According to the present invention, these difliculties are minimized by a particular draw pin construction having means on the draw pin to positively locate the yarn within certain limits in a direction parallel to the draw pin axis.

Accordingly, a primary object of the invention is to provide yarn drawing apparatus including means on the draw pin for guiding the yarn.

A further object is to provide a draw pin of the above character which permits substantially increased draw pin life before maintenance is required.

A further object is to provide a draw pin of the above character which permits the feed rolls and the draw rolls to be narrower and more compact.

A further object is to provide a draw pin of the above character which distributes the wear along the surface of the draw pin.

A further object is to provide a draw pin of the above character which permits the yarn to shift axially along the draw pin only within given limits.

A further object is to provide a draw pin of the above character which arranges the yarn into a filament sheet particularly adapted and oriented for introduction into the nip of a pair of meshed texturing gears.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a more complete understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawing, in which:

FIGURE 1 is a schematic perspective view of draw texturing apparatus including a preferred draw pin constructed according to the present invention.

And FIGURE 2 is a perspective view of an alternative embodiment of the draw pin.

Referring now generally to FIGURE 1, yarn 20 is supplied from a suitable yarn source 22 (illustrated as a spin cake) by a feed mechanism, illustrated as a pair of driven feed rolls 24, and may be guided to feed rolls 24 by a conventional guide element 26 if desired. Yarn 20 next passes around a rigidly mounted draw pin 28, which may be electrically heated if desired, and then through a drawing means, illustrated as a pair of driven meshed gears 30 and 32 which simultaneously draw and texture the yarn. It will be understood that an ordinary draw roll with an associated separator roll, or a pair of nip-forming rolls similar to those illustrated at 24, may be used instead of gears 30 and32 if texturing is not desired. The peripheral speed of gears 30 and 32 is higher than the periphenal speed of feed rolls 24 so that yarn 20 is drawn or elongated in the drawing region between feed rolls 24 and gears 30 and 32. The drawn yarn is next passed through a conventional guide 34 to a suitable take-up mechanism 36, which may be of any desired type although a yarn twister take-up is preferred and is illustrated.

As is illustrated, draw pin 28 includes a cylindrical body portion having its axis mounted substantially parallel to the axes of feed rolls 24 and of gears 30 and 32. Draw pin 28 may be rigidly mounted on a support or frame member 39 by any suitable attaching means, such as by the illustrated stud 37. Although the entire draw pin 28 may be of ceramic construction, in its preferred construction the body of the draw pin is formed of a metal, for example aluminum, and has applied to its cylindrical outer surface an appropriate ceramic coating in order to provide suitable durability or resistance to the abrasive effect of the yarn. A helical radially extending raised ridge or thread 38 is provided on the coated cylindrical surface 40 of draw pin 28, to positively separate adjacent wraps of the yarn and to limit movement of the yarn along the axis of the draw pin. In the preferred embodiment illustrated, ridge 38 defines with the cylindrical surface 40 of draw pin 28 a flat-bottomed helical groove 42 in which yarn 20 runs. Ridge 38 should extend radially above surface 40 sufficiently to positively locate yarn 20 within groove 42, i.e., ridge 38 preferably has a radial extent greater than the thickness of yarn 20. The axial distance on draw pin 28 between adjacent turnsof ridge 38, i.e., the width of groove 42, should be several times the thickness of yarn 20, for reasons which will be explained below.

In the apparatus as thus described, yarn 20- when strung up will assume an equilibrium position within groove 42, so that yarn 20 upon leaving draw pin 28 is delivered to gears 30 and 32. As the yarn continues to run in groove 42, the surface characteristics of the groove in the path contacted by the yarn are slightly modified due to the abrasive action of the yarn. The portion of the groove abraded by the yarn will be slightly polished, increasing its coefiicient of friction and applying a slightly higher draw to the yarn. Since the axis of drawpin 28 is substantially parallel to the axes of feed rolls 24 and of gears 30 and 32, yarn 20 is free to shift its path along the axis of draw pin 28 to any position in groove 42, in seeking a new equilibrium position presenting a minimum draw on the yarn. The entire bottom of groove 42 may thus be polished by the yarn before refinishing of the draw pin surfaceis necessary, rather than a path merely the Width of the yarn -as is conventional. A further particular feature in the illustrated apparatus is that yarn 20, upon leaving draw pin 28, is formed into a filament sheet properly oriented to enter the nip formed by gears 30 and 32 with a minimum danger of breakage of the filaments by the closely meshed teeth. As it leaves draw pin 28, yarn 20 is limited in its movement in either direction parallel to the axis of draw pin 28 by the ridge 38, and thus leaves the draw pin at a position within the limits determined by the width of groove 42. If the apparatus is properly aligned, gears 30 and 32 need have an axial thickness only a little larger than the width of groove 42.

Referring now to FIGURE 2, similar results can be obtained by replacement of the continuous ridge or thread 38 by discrete guide protuberances or fingers 44 which are helically spaced on the outer surface 40 of draw pin 28 so as to positively separate adjacent wraps of the yarn and to permit shifting of the yarn along the axis of draw pin 28 only within a limited range.

The full advantages of the invention are best achieved when the axes of the draw pin, the feed rolls, and the texturing gears or other drawing rolls are all substantially parallel, particularly when these elements are mounted near one another. It should be noted that the illustrated feed rolls 24, which form a nip for gripping the yarn, may be replaced by a conventional single feed roll with a cooperating slightly skewed separator roll. In this case also, the single feed roll axis is preferably parallel to the axis of draw pin 28. Positive separation of adjacent wraps and positive location of the yarn within limits is nevertheless provided by the guide means on the draw' pin even when the draw pin is skewed with respect to the feed rolls or the gears, which thus facilitates stringing up the yarn and reduces the need for critical alignment of the draw pin.

It may be seen from the above description, together with the accompanying drawings, that the present yarn drawing apparatus represents a substantial advance in yarn handling and processing. Draw pins according to the present invention provide a defined helical path on the cylindrical surface thereof for receiving the yarn. The guide means which define the helical path positively locate the yarn on the draw pin within the path, thus facilitating initial stringup of the yarn. When the draw pin axis is properly aligned with the feed and draw rolls, the inherent wear produced by the yarn running on the draw pin surface is distributed over the path, rather than being localized as is necessary with conventional draw pins. This permits substantially increased draw pin life before maintenance is required. Alignment of the drawpin axis to be parallel to the axes of the texturing gears forms the yarn into a filament sheet which is properly oriented to enter between the meshed texturing gears with a minimum danger of breakage of the individual filaments. The improved draw pin construction is simple and economical, and is readily adapted for use with existing drawing and texturing apparatus.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efiiciently attained and, since certain changes may be made in the above constructions without depart ing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In apparatus for drawing a yarn, said apparatus including yarn supply means feeding said yarn at a given rate to a drawing region, and means withdrawing said yarn from said drawing region at a higher rate than said given rate whereby said yarn is drawn, the combination therewith of:

(a) a draw pin rigidly mounted in said drawing region for localizing the point at which said yarn necks down to a smaller diameter, said draw pin having an axis and a yarn-engaging surface about which said yarn is wrapped,

(b) and guide means for separating adjacent wraps of said yarn on said draw pin and for limiting movement of said along the axis of said draw pin.

2. The combination defined in claim 1, wherein said guide means includesraised wrap-separating means extending from said surface to define with said surface a generally helical path for said yarn.

3. Apparatus for drawing a yarn comprising in combination:

(a) yarn supply means for feeding said yarn at a given rate to a drawing region,

(b) yarn drawing means for withdrawing said yarn from said drawing region at a higher rate than said given rate whereby said yarn is drawn,

(0) a draw pin rigidly mounted in said drawing region, said draw pin having an axis and a yarnengaging surface about which said yarn is wrapped,

(d) and raised wrap-separating guide means extending from said surface to define therewith a generally helical path on the surface of said draw pin.

4. The apparatus defined in claim 3, wherein said surface is of ceramic composition.

5. The apparatus defined in claim 3, wherein said surface is cylindrical, and wherein said guide means includes a helical ridge extending from said cylindrical surface and forming therewith a helical groove for receiving said yarn.

6. The apparatus defined in claim 3, wherein said yarn drawing means comprises a pair of meshed yarn texturing gears between which said yarn is passed.

7. The apparatus defined in claim 3, wherein said helical path is several times as wide as the diameter of said yarn.

References Cited by the Examiner UNITED STATES PATENTS 2,423,211 7/ 1947 Vanselow 242-153 2,736,944 3/ 1956 Herbert et a1 2859.5 3,024,516 3/ 1962 Bromley et a1. 2871.3 X

FOREIGN PATENTS 1,043,445 6/ 3 France.

934,383 8/ 1963 Great Britain.

MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, Examiner.

H. S. IAUDON, Assistant Examiner. 

1. IN APPARATUS FOR DRAWING A YARN, SAID APPARATUS INCLUDING YARN SUPPLY MEANS FEEDING SAID YARN AT A GIVEN RATE TO A DRAWING REGION, AND MEANS WITHDRAWING SAID YARN FROM SAID DRAWING REGION AT A HIGHER RATE THAN SAID GIVEN RATE WHEREBY SAID YARN IS DRAWN, THE COMBINATION THEREWITH OF: (A) A DRAW PIN RIGIDLY MOUNTED IN SAID DRAWING REGION FOR LOCALIZING THE POINT AT WHICH SAID YARN NECKS DOWN TO A SMALLER DIAMETER, SAID DRAW PIN HAVING SAID YARN IS WRAPPED, 